The varieties of scientific discovery - ACS Publications

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Georg Lockemann

Muhle Hollenstedt uber Northeim Hannover Translated by Ralph E. Oesper Universily of Cincinnati Cincinnati, Ohio

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In his "Aphorisms" the Goettingen physicist Georg Christoph Lichtenberg (1742-1799) states: "It is strange that only extraordinary men make the discoveries, which later appear so easy and simple." I n fact, the greatest discoveries and inventions are no longer regarded as wonderful and astounding after they are known for a time; daily contact makes them appear quite natural and a matter of course. Attempts have been made to divide the most important discoveries into groups, under the headings: chance, assiduity, genius. However, close examination soon reveals that none of these features can alone bring about a discovery. All three are always involved, though admittedly one or the other may predominate. Even the most favorable chance will be of no avail if i t does not come to the proper obsewer who is capable of drawing the right conclusions from what he has seen. As Goethe astutely remarked (Faust, Part 11) : Has. Fortuue liuked i* with Merit To rhrir fool's nit* ,loth ne'er orrur, 11.111 t1.w r h r Philosouher's Stonr. I swrnr it. The Stone had no ~hhosopher.

Diligent strenuous labor is required in every case before the searching investigator can clarify and make understandable the essence of the nnhoped-for, the unexpected gift, which Fortune in a favorable mood has tossed into his lap. Also, in some cases, it is necessary even to overthrow opinions and "laws" which until then had been accepted as irrefutable axioms. I n all cases, therefore, the third factor "genius" is the most important; without it the discovery could not have occurred a t all. If this intellectual power is absent, all chance observations are nothing, all labor and diligence are in vain. Accordingly, every advance in the understanding of nature, in the conquest of natural forces and the resultant further development of culture and civilization are primarily dependent on the occurrence of unusually endowed investigators, the so-called men of genius. Since the results of scientific researches are published in periodicals and books which are readily available to trained readers, the development of the sciences may be compared to a drama presented on a stage. I n general the performance involves competent "actors" who appear and play their parts well in that they advance the knowledge of nature by their research contributions. But a t times difficulties arise in the further development of the action, and the intervention of a "heroic character" becomes a necessity. Now it The more lengthy German text of this paper appeared in Nalurwissensehaftliehe Rundschau, June 1957, pp. 219-24. The publishers have kindly authorized the present translation.

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The varieties of scientific Discovery

becomes a question whether the unseen director will give the proper cue, or whether the appointed character already is standing in the wings and can appear on the stage a t the crucial moment. The history of science reveals that this actually takes place in many instances; in fact sometimes not merely one actor waits in the wings for the cue but rather two or three walk on to the stage a t the same time. Indeed, there some times are premature actors, who in brilliant fashion foresee far in advance the coming difficulties or crises in the action; impatient, they do not wait for the cue but to the consternation of the other actors appear in their midst ahead of time and are pushed aside as nnwanted noncomforming interlopers. Not until much later do the other actors and the audience realize that these unwelcomed persons had sensed the correct thing much in advance and had meant well. Sometimes this realization comes only after they themselves have departed from the scene. However, there is a third class of discoverers who, totally unconcerned about the unfolding of the plot, make a discovery which a t first is completely inexplicable, and with this they jump quite unexpectedly into the midst of the peaceful proceedings. They demolish all doubts of the correctness of their discovery by the sheer weight of the experimental evidence in that a t the same time they create a new line of research which until then had been looked on as impossible. Well-Timed Discoveries

Timely discoveries are made when the whole trend of development of the scientific investigation is in their direction. Conjectured and awaited, they are "in the air" and the great man who makes them appears opportunely. Among the many examples that may be cited are rather many in which more than one person made the discovery a t almost the same time. Though this may be beneficial to the science itself, it often proves painful for the individual investigators concerned. Such essentially simultaneous discoveries usually give rise to the unpleasant and highly pnblicized priority disputes. Each of the happy discoverers is of the opinion-and rightly so-that the great discovery is his alone and he defends his claim with all his might. The pure joy of the discovery is soon sullied when he finds that he must spend much time and energy in upholding his rights; the disputes forced upon him rob him of his peace of mind, and this without any benefit whatever to science. The following example selected from among the many instances of discoveries made independently by

two or even more individuals will illustrate such occurrences and their correlative features: The science of mathematics, confined to analytical methods, had reached its limits in the second half of the seventeenth century. There was a glaring need for a new procedure for solving problems that were obviously beyond the capabilities of the known systems of calculation. I n close succession, two great minds came forward with new ideas presenting the same basic thoughts in a somewhat divergent form. They were: the Englishman Isaac Newton (1643-1727) with his method of fluxions, and the German Gottfried Wilhelm Leibniz (1646-1716) with his differential and integral calculus. Though they had arrived a t the brilliant end-result independently, their lives henceforth were embittered by priority disputes, largely forced on them by their embattled partisans, who of course were men of far lower stature. A similar controversy involving priority arose a century and a half later with respect to the discovery of the principle of the conservation of energy. The principals were Julius Robert Mayer (1814-1878) and Hermann Helmholtz (1821-1894). After rejection by Poggcndorf, the editor of the Annalen der Physilc, Mayer's "Remarks on the Forces of Inanimate Nature" was published by Liebig in 1842 in his Annala der Chernie und Pharmazie hut attracted no attention. Five years later, Helmholtz put out his treatise "On the Conservation of Energy" but would not acknowledge Mayer's priority. At this same time the highly educated English brewer James Prescott Joule (18181889) was making measurements of the mechanical equivalent of heat, and as early as 1837 the German chemist Carl Friedrich Mohr (1806-1879) had developed similar ideas without being able to come to a clear-cut decision on the matter. Several similar instances should be mentioned a t least briefly. Justus Liebig (1803-1873) and Jean Baptiste Dumas (1800-1884) contested the other's priority regarding the recognition of the natural cycle of materials (184041). The theory of the self-chaining of carbon atoms advanced as early as 1852 by the Austrian chemist Friedrich Rochleder (1819-1874) was again set forth (1857) almost simultaneously by the Scotchman Archibald Couper (1831-1892) and the German chemist August Kekul6 (1829-1896), and through the concept of valence the structure theory of organic chemistry was founded a t the same time. The hexagonal structure of benzene, developed in 1865 by Kekult? on the basis of a dream vision, proved so fruitful for the further development of the aromatic compounds that a "Benzene Celebration" was held in honor of its 25th anniversary, but it had already been proposed in 1861 by the Austrian chemist Joseph Loschmidt (1821-1895). A striking example showing that not only discoveries but also inventions sometimes are "in the air" and that occasionally different scientists are working on the same problem unknown to each other is provided by the discovery of the method of preparing alizarin in the laboratory. The German chemists Carl Graehe (1841-1927) and Carl Liebermann (1842-1914) submitted their application for a patent for making this coloring matter of the ancient madder on June 25, 1869, whereas William Henry Perkin (1838-1907)

applied for a patent in London covering the same process just one day later. Other noted instances of the many discoveries that were announced a t practically the same times include the formulation of the periodic system of the chemical elements by Lothar Meyer (183W1895) and Dmitri Mendeleev (1834-1907) in 1869 and the founding of stereochemistry and the announcing of the theory of the asymmetric carbon atom in 1874 by the Hollander Jacobus Henricus van't Hoff (1852-1911) and the Frenchman Jules Achille le Be1 (1847-1936). Premature Discoveries

This group includes those discoveries that are made before the general state of scientific investigation affords the possibility of accepting them intelligently. The premature discoverers are ahead of their times, their findings are generally rejected, and they sometimes are even regarded as crackpots. Their speech is not understood by their contemporaries. What they themselves see clearly appears confused and obscure to others. Accordingly, they perhaps go through life misunderstood and they strive vainly to overcome the "resistance of the obtuse world." A prime example of a chemist who was forgotten because his great discovery came too early was Jeremias Benjamin Richter (1762-1807) who by introducing mathematics into chemistry founded chemical stoichiometry and discovered the neutralization law. I n his minor post as "arcanist" a t the Royal Porcelain Works a t Berlin he received no attention for his fundamental discoveries regarding the neutralization process and the constancy of combining ratios. His ideas were really appreciated only long after his death when they became dominant building blocks in the entire chemical science. The young English scientist J. J. Waterston (18111883) suffered a similar tragic fate. In 1845 he submitted to the Royal Society a paper in which he developed his ideas on the gaseous state. It was quietly interred in the files as being of no consequence where it was accidently discovered 30 years later by Lord Kelvin. To the latter's amazement, he found that it contained the basic features of the kinetic theory of gases, which in the interim had been set up by the German physicists August Karl Kronig (1822-1879) and Rudolph Clausius (1822-1888) and which for a quarter of a century had already played a leading role in chemistry and physics. Inquiries were then instituted about Waterston and i t was learned that overcome by despair he had gone to India and left no further trace. The history of medicine likewise contains instances of unappreciated premature discoveries. The GermanHungarian physician Ignaz Semmelweis (1818-1865) while working in the maternity wards of the Viennese hospitals became well acquainted with childbed fever whose ravages were claiming more and more lives. He came to the opinion (1847) that the deadly poison was being carried from woman to woman by the physicians themselves on their dirty hands and instruments. Since it was well known that the odor arising from putrefying masses could be removed by chlorine, Semmelweis thought i t might also be useful with suppurating cases. Accordingly he introduced the practice Volume 36, Number 5, May 1959

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of washing the hands and instruments with chloride of lime solution and had much success. However, this measure was rejected by most of the physicians, probably because he undiplomatically called those who did not adopt his procedure "murderers." The disdain which greeted his discovery and the treatment he himself received from some of his professional colleagues affected him so deeply that he was close to insanity for a time. Actually he was the discoverer of practical disinfection and after his death a monument was erected to his memory in Budapest carrying the inscription "The savior of mothers." Semmelweis' chlorine water had been practically forgotten when the English surgeon Joseph Lister (1827-1912) in 1867 introduced carbolic acid as disinfectant. It was more than a generation after Semmelweis that Robert Koch (1843-1910) in 1881 a t Berlin laid down the scientific bases of disinfection and aseptic practices. There are also instances of misunderstood premature discoveries which occurred without making any stir in the scientific world but in which the indifferent reception was accepted quietly by the discoverer with no apparent psychic or other effects. A typical instance is that of Gregor Mendel (1822-1884), the discoverer of the law of biological heredity. I n the garden of the monastery a t Briinn (now Brno) this Augustinian monk made systematic experiments on the crossing of various strains of plant hybrids and in 1865 came to a knowledge of the laws governing the transmission of certain characteristics, i.e., of regularities which have now been generally accepted under the name of Mendelian laws. However, he published his findings and conclusions in an obscure periodical, and these fnndamental discoveries remained effectively concealed from the outside world. Consequently, it was possible for these same discoveries to be made again, "at the proper time" a generation later, in 1900, i.e., after botanical research had progressed sufficiently to handle and appreciate this problem properly. These later discoverers, who announced their results a t approximately the same time, were: the German bob anist Carl E. Correns (1864-1933), the Hollander Hugo de Vries (3848-1935), and the Austrian Erich von Tschermak (1871). I n this connection i t is well to remember the rule: "He becomes the true discoverer who establishes the truth; and the sign of the truth is the general acceptance. . . . I n science the credit goes to the man who convinces the world, not to the man to whom the idea first occurs." (Dnbos, "The White Plague," 1952). Unforeseen Discoveries

This group includes those discoveries which do not lie in the orderly course of scientific research, which are not made before the times are ready for them, and which cannot be anticipated or a t most only in the wild phantasies of a Jules Verne. They fall entirely outside the usual bounds of strictly scientific investigations, and must be looked on as the fruit of unbridled ingenious notions except that by an appropriate experiment it is possible to confirm them to the satisfaction of even the most incredulous scoffers. Such unexpected glimpses into the "interior of nature" are granted but seldom to individual researchers and then in a singularly fortunate moment. The discovery is completely 222

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outside the accustomed limits of the line of study; it reveals characteristics and powers of nature which up till then had been held to be quite impossible. The investigator himself is so astounded by the unlookedfor discovery, is so dazzled by the blazing new light, that he requires a certain period of inner composure to convince himself that he is not the victim of selfdeception. No competitors enter the picture. There is no opportunity for priority debates to arise. Those who are gifted with hindsight, who subsequently invariably claim to have known everything beforehand, must keep silent under these circumstances. Obviously a particularly important role is played by chance in these unanticipated discoveries. The history of physics is the most fertile source of unlooked-for discoveries. Typical instances include the discovery of electromagnetism in 1820 by the Danish scientist Hans Christian Oerstedt (1777-1851) and that of the catalytic action of platinum in 1820 by the German chemist Johann Wolfgang Dohereiner (1787-1851). When the German chemist Robert Bunsen (1811-1899) and the German physicist Gustav Kirchhoff (1824-1884) were working together on the phenomena which became the basis of spectrum analysis, they grew so excited that the usually collected and grave Bunsen exclaimed "If the dark D-line actually appears in the spectrum, Kirchhoff, I believe I shall go crazy." When, in 1896, Konrad Wilhelm Rontgen (1845-1923) first observed the penetrating power of the X-rays, he shut himself in his laboratory for days to prove to himself by intensive experimentation that he had not deceived himself. That this discovery had not previously come to the highly skilled physicist Philipp Lenard (1862-1947) who had previously done such outstanding work on cathode rays, was doubtless due to the absence of the necessary element, chance. The eminent physical chemist, teacher, philosopher Wilhelm Ostwald (1853-1932) believed everything between heaven and earth can be expressed in a formalized understandable form. Among others, he developed a "good fortune formula" with which however he did not have much success either with his professional colleagues or others to whom he attempted to apply this mode of assessing real success and happiness. If, however, this concept of good fortune is applied to the various discoverers it will be found from what has been stated above, that the surprised discoverers were the happiest, the premature discoverers the least happy, while those whose discoveries were timely stand between because the joy in their discoveries is so often clouded by priority disputes. The preceding text applies to actual discoveries and true discoverers, who in terms of the analogy to a drama being presented before the public really appear in the performance. There are also those who stay in the wings, or if they do appear their stay on the stage is only temporary. Accordingly, to the three positive groups of discoveries there should be added two negative groups, the discoveries that were missed and those that were imagined. Missed Discoveries

A missed discovery is one that a scientist brushes by in the course of his studies without being aware of its

presence, or one which he fails to achieve because for some reason or other his investigation is broken off just as the imminent discovery is about to come to light. Obviously in all such cases this near-miss becomes apparent only after the actual discovery has been made by some one else. Even though the ofteuproposed Journal of Futile Experiments has never been published, the history of science discloses that the number of discoveries that have been allowed to slip through the fingers of various workers is extensive; perhaps it is the largest of all the groups. The classic example is found in the long antecedent history of the discovery of oxygen, which extends over about 250 years from the time of Leonardo da Vinci (1452-1519). To be sure, these investigators in the seventeenth century, like da Vinci himself, really should be placed in the category of premature discoverers. The French physician Jean Rey (d.1645) and the English scientists Ralph Bathurst (1620-1704), Robert Hooke (1633-1703), and John Mayow (1645-1679) were on the track of the mysterious element but could not run it down. Free oxygen was generated for the first time by the Danish polyhistor Ole Borch (16201691) hut he could not recognize it as such. Even after the pneumatic trough was devised in 1727 by Stephen Hales (1677-1761), an English rural clergyman, and thus provided the means of collecting individual gases separately, it was more than a half a century before oxygen was eventually actually "discovered." The Paris apothecary Pierre Bayen (1725-1787) furnished a model example of a missed discovery. He obtained a gas, which he referred to as Jluide elastique, by heating red oxide of mercury, and when he heated metallic mercury in this gas i t was again transformed into "mercurius praecipitatus per se." However, he did not recognize the true nature of the gas. Had he performed the simple experiment of inserting a glowing splint into the gas he could have laid claim to being an actual discoverer of oxygen. But since he omitted this crucial experiment, he was forced to concede this fame to the English cleric Joseph Priestley (1733-1804), who made the decisive experiment on August 1, 1774. However, it later became known that Priestley himself had been preceded in this discovery by the GermanSwedish apothecary Carl Wilhelm Scheele (17421786) who a few years earlier (1771-72) had prepared " fire air." During this period of near discovery of oxygen, the phlogistic hypothesis, that had been set up by the Halle professor Georg Ernst Stahl (16601734) on the basis of the teachings of Johann Joachim Becher (1635-1682), had become so thoroughly entrenched that even the discoverers of oxygen, namely Priestley and Scheele, remained firm adherents of this hypothesis to the end of their days. The great theoretician Antoine Laurent Lavoisier (1743-1794) had to come on the scene to complete the discovery of oxygen, whose protracted discovery offers a true instance of a discovery-synthesis. Since even the chemical Joves sometimes nod, it is not too surprising that both of the famed chemical friends, Liebig and Wohler, experienced the chagrin of missing the discovery qf discoveries in chemistry, i.e., the discovery of a new element. In 1826, Justus Liebig (1803-1873) then a young professor a t Giessen, read with an emotion akin to shock that the French

apothecary Antoine Jerome Balard (1802-1876) a t Montpellier had discovered a new element in Mediterranean Sea, water. This heavy red-brown liquid evolved vapors of the same color whose terrible odor led Gay-Lussac to suggest that the new element be named bromine from the Greek bromos (stench). The deeply affected Liebig arose, went to his collection of chemicals, and took down a bottle which he had placed on a shelf more than a year previously. It contained a red-brown evil-smelling liquid and had been obtained by him from the mother liquor of Kreuznach spring. He had put it aside for later study assuming off-hand that it was iodine chloride. Liebig never recovered from this grave disappointment, especially since never again did he have another chance to discover an element. He sought to salve his wounded vanity by sneeringly remarking, "Balard did not discover hromine, rather hromine discovered Balard'!, a reaction branding Liebig as a poor loser. Actually the Kreusnach apothecary Carl Lowig (1803-1890), who later was professor a t Zurich and Breslau, experienced the same disappointment. He too had shown the presence of the new element in the Kreuznach mother liquor but had delayed publishing his finding pending more experiments, which he actually carried out later. Liebig's friend, Friedrich Wohler (1800-1882) whose fame was first founded by his isolation of aluminum in 1827, had the opportunity of discovering two hitherto unknown elements and missed both chances. I n 1830 he was studying a Mexican mineral turned over to him by Alexander von Humboldt, and in which the mineralogist Del Rio of Mexico City 30 years before believed he had found an unknown element which he named "erythronium" because of the red color of its oxide and salts. However, led astray by the French chemist Collet-Descotil, Del Rio later withdrew his announcement. At this time Wiihler was recovering from an attack of hydrogen fluoride vapors and sent the specimen to his student Nils Gabriel Sefstrom (17871845) a t Fahlun for further examination. The latter found that the Mexican mineral and also a certain Swedish soft iron unquestionably contained an unknown element. He named it vanadin (vanadium) in honor of the Nordic goddess Vanadis (identical with Freya the goddess of love). The letter which Berzelius sent Wohler, both chiding and commiserating him for missing this chance, is a classic in the history of the discovery of the elements. The other instance involved a mineral from Massachusetts, later named columbite, which was suspected of containing an unknown element. The latter was suspected of being identical with tantalum, discovered in 1802 by the Swedish chemist A. G. Ekeberg (17671803). Wohler likewise was trying to clear up this question but did not carry his studies to completion. However, in 1844, Heinrich Rose (1795-1864) in Berlin showed that the disputed component in columbite was not tantalum hut a new element, which he named niobium from Niobe, the daughter of Tantalus. Wohler's reaction when he heard this news was in sharp contrast to that of Liebig when the latter learned of the discovery of discovery of bromine. Wohler wrote to Berselius: "I do not feel aggrieved because this has eluded me, and I heartily wish our good Heinrich every joy in the discovery." Volume 36, Number 5, May 1959

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Imagined Discoveries

Behind the scenes of the scientific research stage there can be found some peculiar types of "discoverers," who work diligently but who are imbued with the hope and firm determination some day of making a great discovery. Possessed of a fixed idea, they pursue it like a mirage, looking neither to right nor left, and eventually they come to believe that the image is the real thing. They lose the ability to make a reasoned objective judgment; they become prisoners of their own imaginations. If they then decide to appear on the stage before the public and exhibit their alleged findings, it sometimes happens that they are greeted with wondering looks and even receive recognition in some instances. However, such fame is fleeting. I t quickly vanishes when faced with serious scientific scrutiny and may be transformed even into the opposite of honor provided it does not meet the milder fate of being forgotten. No names connected with such alleged or supposed discoveries will be given here; it is sufficient to recall several cases that occurred within fairly recent times. I n 1923 great excitement was aroused by the announcement that mercury had been transformed into gold by electrical action. Because of the impact of the modern theory of transmutation this claim was not rejected offhand even in authoritative circles (except by those who knew the "discoverer" intimately). Nevertheless, it took two years of intensive research to clear up the matter conclusively; several competent workers finally tracked down the source of the gold. It must be admitted that several facts that in themelves had scientific value were brought to light during these elucidating explorations. Works of Art Not Discoveries

If in connection with the consideration of the varieties of discovery in the natural and physical sciences

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a look is also directed toward the problem of the purely mental discoveries, closer examination reveals that the two provinces possess basic differences. I n the case of scientific discoveries-in conformity with the sense of the word-these deal with the revelation of something that was already present hut which was merely not apparent t o the human perception. Obvious examples are radioactivity, discovered only some six decades ago, and the more recently discovered transformation on earth of hydrogen into helium accompanied by the release of tremendous amounts of energy. Such secrets of nature remained hidden from the human mind until they were revealed to some favored investigator a t some propitious time. Whether this disclosure came sooner or later had no effect on the features of what was discovered, because the latter was always there and was merely waiting to be found and recognized for what it was by the inquiring worker. The situation is entirely different with respect to the products in the province of purely mental creativity. Such works by musicians, poets, writers, artists, and others are not already in existence, they have to be created. Whereas i t is a matter of small importance who actually makes scientific discoveries, in the creative field the essential features of the work depend above all on the character and abilities of the person responsible. The masterpieces of such men as Goethe, Michelangelo, Shakespeare, Mozart, etc., happen but once and as unica are irreplaceable. They would not have been produced by anyone else. If on August 28, 1749, a t Frankfurt am Main, the midwife had not expertly taken extreme measures with the apparently still-horn infant until she could trinmphantly call out "The boy lives," the human intermaxillary bone would have been discovered long since none the less, but there would have been no 'Taust" or any of the other priceless Goethe creations. No other writer, no matter how accomplished, could have replaced them for us.